JESS

Difference between Jess and Prolog

• Jess is different than some Rete-based systems in that it includes both a kind of backwards chaining and a construct called defquery which lets you make direct queries of the working memory. Both of these help Jess a better fit for some Prolog applications, but they don't make Jess into a Prolog-like system.

• Prolog is optimized, in a sense, for space, at the cost of speed. Jess (and its Rete algorithm) is optimized for speed at the cost of space.
  

• The Rete algorithm is all about computing things -once- so they never need to be recomputed, and then reusing them. Prolog's approach is targeted at exploring large numbers of possibilities once, while Rete is aimed at exploring medium-sized numbers of possibilities repeatedly.